Wellbore Shut Off Valve with Hydraulic Actuator System

ABSTRACT

A wellbore shut-off valve is operably associated with a valve actuator so that the shut-off valve can be selectively moved between open and closed conditions when desired rather than opening and closing occurring automatically as portions of the production assembly are removed or replaced in the wellbore.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to systems and methods forisolating or closing off a wellbore or a portion of a wellbore.

2. Description of the Related Art

During operation of a hydrocarbon production well, it is sometimesnecessary to shut off the well or a portion of the wellbore below aparticular point. If the well remains live while, for example, a pump isbeing removed from the production tubing assembly, pressurized fluid canbe forced to the surface very quickly, resulting in a dangeroussituation at the wellhead and possibly reducing the ability of the wellto produce further. Another example of equal importance would involvecontrolling fluid losses to the formation which could permanently damagethe formation. To shut-off the wellbore, a shut-off valve, or barriervalve, can be included in the production tubing assembly.

SUMMARY OF THE INVENTION

The present invention provides a wellbore shut-off valve that isincorporated within a wellbore production string in conjunction with anassociated valve actuator device. In a preferred embodiment, theshut-off valve comprises a ball valve which can be moved between openand closed conditions. A currently preferred embodiment for the valveactuator is a stroker tool having a shifting sleeve that can bepositively moved between first position, wherein the shut-off valve ismoved to the open condition and a second position, wherein the shut-offvalve is moved to the closed condition. In a further preferredembodiment, the valve actuator is hydraulically-actuated.

The shut-off valve and actuator may be made up into a production tubingassembly that is then disposed into a wellbore. Preferably, the shut-offvalve is landed in a packer. The shut-off valve can be placed above orbelow a lower completion packer. When it is necessary to remove aportion of the production tubing string above the shut-off valve, thevalve actuator is operated to cause the shut-off valve to close. Theupper portions of the production tubing string can be removed bydetaching the valve actuator from the shut-off valve and thenwithdrawing the detached upper portions from the wellbore.

Thereafter, the production tubing string can be reinserted into thewellbore and reattaching the valve actuator to the shut-off valve. Whenreattachment occurs, the shut-off valve is not automatically reopened.Because the valve remains closed, wellbore operators are able to make upthe tubing hanger arrangement at the surface before opening the shut-offvalve. When it is desired to reopen the flowbore of the productionstring, the valve actuator is actuated to move the shut-off valve backto the open position.

In another aspect of the invention, operation of the valve actuator maybe controlled by a programmable controller that is programmed tocoordinate operation of the shut-off valve with another deviceassociated with the well production system. In a preferred embodiment,the controller controls the valve actuator in response to a condition ofoperation for a fluid pump within the production assembly. When the pumpis turned off, the controller detects this condition and commands thevalve actuator to close the shut-off valve. The controller can alsocommand the valve actuator to open the shut off valve in connection withthe operation of starting or restarting the fluid pump.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages and other aspects of the invention will be readilyappreciated by those of skill in the art and better understood withfurther reference to the accompanying drawings in which like referencecharacters designate like or similar elements throughout the severalfigures of the drawings and wherein:

FIG. 1 is a side, partial cross-sectional view of a wellbore having anupper production string assembly being disposed therein.

FIG. 2 is a side, partial cross-sectional view of the wellbore shown inFIG. 1, now with the upper production string assembly having been landedand secured to a lower production string assembly in the wellbore.

FIG. 3 is a side, partial cross-sectional view of the wellbore shown inFIGS. 1 and 2, now with a portion of the upper completion assembly beingremoved from the wellbore.

FIG. 4 is a side, one-quarter cross-sectional view of a portion of anexemplary valve actuator in accordance with the present invention, in afirst position,

FIG. 5 is a side, one-quarter cross-sectional view of the exemplaryvalve actuator portion of FIG. 4, now in a second position.

FIG. 6 is a cross-sectional view taken along lines 6-6 in FIG. 4.

FIG. 7 is a side, cross-sectional view of portions of an exemplaryshut-off valve in accordance with the present invention, with the valvein a closed condition.

FIG. 8 is a side, cross-sectional view of the portions of the exemplaryshut-off valve shown in FIG. 7, now with the valve in an open condition.

FIG. 9 is a schematic representation of an arrangement wherein acontroller controls operation of the valve actuator based upon theoperating condition of an electrical submersible pump within theproduction assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring first to FIGS. 1 and 2, there is depicted an exemplarywellbore 10 which has been drilled into the earth 12 and is lined withcasing 14 which will extend upwardly toward the surface of the wellbore10. The casing 14 defines a central flowbore 16. The wellbore 10contains an exemplary production string assembly which will be used toillustrate the invention. It is noted that, in this example, the sectionof the wellbore 10 which is depicted is representative of an upperpump-assisted completion within the wellbore 10 and that one or moreadditional completions may be located below the wellbore portion that isshown. As a result, a lower portion of production tubing string 18 isshown extending downwardly within the flowbore 16 from lower packer 20.A landing anchor 22 extends axially upwardly from the packer 20.Collectively, the lower production tubing string portion 18 and elementssuspended below it, as well as the packer 20 and anchor 22 may bethought of as a lower completion, generally designated as 24.

FIG. 1 illustrates an upper completion, generally designated as 26,being disposed into the flowbore 16 in the direction of arrow 28. InFIG. 2, the upper completion 26 has been landed within the anchor 22 ofthe lower completion 24. The upper completion 26 is run in on an upperstring of production tubing 30 (see FIG. 2) and defines an axialflowbore 32 along its length so that hydrocarbon production fluids maybe transmitted to the surface of the wellbore 10.

Beginning at its lower end and moving upwardly, the exemplary uppercompletion 26 includes a wellbore shut-off valve 34 with a downwardlyextending latching portion 36. The latching portion 36 may take the formof collets or other devices which permit it to be locked together withthe anchor 22. The shut-off valve 34 preferably takes the form of a ballvalve in which a ball having a flowbore is rotated within a flowbore toselectively block and unblock the flowbore 32. The ball is rotated by ashifting member that is biased toward a fail safe position by a fluidspring or mechanical spring. A suitable ball-type shut-off valve for useas the shut-off valve 34 is the Halo Barrier Valve, which is availablecommercially from Baker Oil Tools of Houston, Tex. In FIG. 1, theshut-off valve 34 is shown in a closed position since the ball member 38is shown to be rotated so that the flow path 40 formed within isoriented at approximately 90 degrees from the axis of the flowbore 32 sothat fluid cannot pass through the shut-off valve 34. In FIG. 2, thevalve 34 is shown in an open condition such that the flowbore 40 of theball member 38 is aligned with the flowbore 32 such that fluid may passthrough the valve 34.

The shut-off valve 34 is operably associated with a valve actuator 42.The valve actuator 42 is preferably operated from the surface of thewellbore 10 by hydraulic close and open lines 44, 46, respectively,which are fluid conduits. When interconnected with the shut-off valve34, operation of the actuator 42 will cause the valve 34 to be movedbetween its open and closed conditions. A suitable actuator for use asthe valve actuator 42 is the hydraulic Stroker tool availablecommercially from Baker Oil Tools of Houston, Tex. Portions of theactuator 42 are depicted in greater detail in FIGS. 4-6 and will bedescribed in greater detail shortly.

Also included in the upper completion 26 is a shear out safety joint 48through which the close and open lines 44, 46 are passed. The shear outsafety joint 48 consists of two joint halves 50, 52, which can bereadily disconnected, such as by shearing a set of shear screws, torelease the two halves 50, 52 from one another. This permits a quickrelease of components within the upper completion 26. A perforated pupjoint 54 is incorporated into the upper completion 26 above the safetyjoint 48 and immediately below an electrical submersible pump (ESP) 56.An ESP packer 58 is located above the ESP 56 and, in FIG. 2, is shownset against the flowbore 16 to secure the ESP 56 in place within theflowbore 16. An electrical power cable 60 extends from the surface ofthe wellbore 10 downwardly to the ESP 56. A seating nipple 62 is used toaffix the ESP packer 58 to the ESP 56. An additional safety valve 64 maybe incorporated into the upper completion 26.

FIGS. 4-6 illustrate portions of an exemplary valve actuator 42. Thevalve actuator 42 basically includes an outer, generally cylindricalhousing, generally indicated at 66. An interior sleeve 68 is locatedradially within the housing 66 and is axially moveable with respect tothe housing 66. A radial space 70 is defined between the housing 66 andthe sleeve 68. A central annular fluid seal 72 resides within the space70 and divides the space 70 into upper and lower fluid chambers 74, 76respectively. The upper chamber 74 is defined axially by the centralseal 72 at its lower end and by an upper fluid seal 78 at its upper end.The lower fluid chamber 76 is defined axially by the central seal 72 atits upper end and by a lower fluid seal 80 at its lower end. A firstfluid port 82 is disposed through the housing 66 and is interconnectedwith the close line 44. The first fluid port 82 permits fluidcommunication between the close line 44 and the lower fluid chamber 76.As hydraulic fluid is flowed into the lower fluid chamber 76 from theclose line 44, fluid pressure is exerted upon the lower fluid seal 80and urges the interior sleeve 68 downwardly to the position illustratedin FIG. 5, expanding the lower fluid chamber 76. A second fluid port 84is also disposed through the housing 66 and is interconnected with theopen line 46. The second fluid port 84 provides fluid communicationbetween the open line 46 and the upper fluid chamber 74. As hydraulicfluid is flowed into the upper fluid chamber 74, fluid pressure isexerted upon the upper fluid seal 78 and urges the interior sleeve 68upwardly to the position depicted in FIG. 4, expanding the upper fluidchamber 74.

The lower end of the interior sleeve 68 presents a shifting member 86(see FIGS. 2, 7 and 8). The shifting member 86 is shaped and sized toengage operating portions of the shut-off valve 34, as will be describedshortly.

FIG. 4 depicts the valve actuator 42 in a first position wherein thesleeve 68 and shifting member 86 are axially raised with respect to thesurrounding housing 66 of the valve actuator 42. FIG. 5 illustrates thevalve actuator 42 in a second position wherein the sleeve 68 andshifting member 86 are axially lowered with respect to the housing 66.FIGS. 7 and 8 show the shifting member 86 reversibly connected with theshut-off valve 34. As can be seen there, the shut-off valve 34 includesan outer housing, indicated at 88 which retains the ball member 38. Asleeve assembly 90 is axially moveable within the housing 88 and, whenmoved axially, shifts the ball member 38 between the closed conditionshown in FIG. 7 and the open condition shown in FIG. 8. The upper end ofthe sleeve assembly 90 presents a number of inwardly directed colletfingers 92. The collet fingers 92 are shaped and sized to snap intoengagement with engagement portions 94 of the shifting member 86.

In operation, the upper completion 26 is run into the wellbore 10, asdepicted in FIG. 1, and then landed in the anchor 22 so that the uppercompletion 26 is secured to the lower completion 24. During run-in, theshut-off valve 34 is in the closed position. Upon being landed in theanchor 22, the valve actuator 42 is actuated to move the shut-off valve34 to the open condition, as depicted in FIG. 2. In the open condition,production fluid may be flowed upwardly from the lower completion 24through the flowbore 32 of the upper completion 26.

During production, it may be desirable to shut-off the wellbore 10 andremove the upper completion assembly 26. One reason for doing this mightbe to service the ESP pump 56. To remove the upper completion assembly26, the valve actuator 42 is operated to cause the shut-off valve 34 tomove to its closed condition, thereby blocking fluid flow upwardlythrough the flowbore 32. Fluid flow is also prevented going down thewellbore 10, preventing fluid losses to the surrounding formation.Hydraulic fluid is flowed through the close line 44 and into the upperfluid chamber 74 to move the shifting member 86 upwardly, therebyclosing the valve 34. Then the valve actuator 42 is detached from theshut-off valve 34 by detaching the engagement portions 94 of theshifting member 86 from the collet fingers 92 of the sleeve assembly 90.The upper completion assembly 26 may be withdrawn from the wellbore 10.At this point, the ESP 56 may be serviced or replaced and othermaintenance or repairs may be made to the upper completion 26.

In order to reestablish production from the wellbore 10, the uppercompletion 26 is run into the wellbore 10 and the valve actuator 42 isthen reattached to the shut-off valve 34 by reattaching the engagementportions 94 of the shifting member 86 with the collet fingers 92 of thesleeve assembly. When this occurs, the shut-off valve 34 will remain inthe closed condition. Well operators will be able to make up the tubinghanger arrangement at the surface before opening the shut-off valve 34.When it is desired to reestablish production, hydraulic fluid is flowedthrough the open line 46 to the valve actuator 42 to cause the shut-offvalve 34 to be moved to its open condition (FIG. 8). The ESP 56 may berestarted to cause production to occur once more.

In a further preferred aspect of the invention, operation of the valveactuator 42 is responsive to the condition of another device within theupper completion assembly 26. In one exemplary embodiment, the valveactuator 42 is operated based upon the operating condition of the ESPpump 56. FIG. 9 is a schematic representation of such a control schemewherein a controller 94 is interconnected with the ESP 56 and a fluidpump 96. The fluid pump 96 is typically surface-based and provideshydraulic fluid through the close and open lines 44, 46 to the valveactuator 42. The controller 94 may be a programmable processor orgeneral purpose digital processing system, such as a personal computerof a type known in the art with suitable software or code for conductingthe operations described herein. The controller 94 is equipped with oneor more sensors, indicated schematically at 98, which are capable ofdetecting whether the ESP 56 is on or off. Control line 100 extends fromthe controller 94 to the pump 96. According to an exemplary controlscheme using the controller 94, the controller 94 detects whether theESP 56 is operating to pump fluid through the upper completion 26 or,alternatively, if the ESP 56 is not operating. If the controller 94detects that the ESP 56 is not operating, it commands the pump 96 toflow fluid through the close line 44 in order to move the shut-off valve34 to its closed condition. Therefore, the upper completion 26 may beremoved after the operation of turning the ESP 56 off. Also according tothe exemplary control scheme, the controller 94 will command the pump 96to flow fluid through the open line 46 when it detects that the ESP 56is operating or is being started up. This mode of operation will helpprevent fluid from being lost to the surrounding subterranean formation,thus helping to prevent formation damage. By reopening the shut-offvalve 34 prior to or in conjunction with starting of the ESP 56, one canensure that there will be a column of fluid within the flowbore 32 ofthe upper completion 26 when the ESP 56 starts operating, therebyreducing operating stress on the ESP 56.

It can be seen that the shut-off valve 34 and the valve actuator 42collectively provide a controllable shut-off valve assembly which can beused to selectively open and close off the wellbore 10 in accordancewith a user's desire or a predetermined programmed scheme via controller94. Optionally, a shut-off valve assembly constructed in accordance withthe present invention may also include a fluid pump 96 and a controller94 for operation of the fluid pump 96 in response to the condition ofanother component with the upper completion 26.

Those of skill in the art will recognize that numerous modifications andchanges may be made to the exemplary designs and embodiments describedherein and that the invention is limited only by the claims that followand any equivalents thereof.

1. A shut-off valve assembly for use in selectively closing off asection of wellbore to fluid flow, the assembly comprising: a shut-offvalve incorporated within a completion string within the wellbore, theshut-off valve being moveable between an open condition wherein fluidmay flow through the completion string, and a closed condition, whereinfluid flow through the completion string is blocked; and a valveactuator incorporated within the completion string and associated withthe shut-off valve, the valve actuator operating the shut-off valvebetween its open and closed conditions.
 2. The shut-off valve assemblyof claim 1 wherein the shut-off valve comprises a ball valve.
 3. Theshut-off valve assembly of claim 1 wherein the valve actuator ishydraulically actuated.
 4. The shut-off valve assembly of claim 1wherein the valve actuator further comprises: a housing; a sleevemoveably disposed within the housing; and a shifting portion affixed tothe sleeve, the shifting portion being operable to move the shut-offvalve between open and closed conditions upon movement of the sleevewith respect to the housing.
 5. The shut-off valve assembly of claim 1further comprising a programmable controller operably associated withthe valve actuator to cause the valve actuator to operate the shut-offvalve between open and closed conditions in accordance with apredetermined scheme.
 6. The shut-off valve assembly of claim 5 whereinthe controller is operably associated with the valve actuator by controlof a fluid pump supplying hydraulic control fluid to the valve actuator.7. A shut-off valve assembly for use in selectively closing off asection of wellbore to fluid flow, the assembly comprising: a shut-offball valve incorporated within a completion string within the wellbore,the shut-off ball valve being moveable between an open condition whereinfluid may flow through the completion string, and a closed condition,wherein fluid flow through the completion string is blocked; and a valveactuator incorporated within the completion string and associated withthe shut-off valve, the valve actuator operating the shut-off valvebetween its open and closed conditions.
 8. The shut-off valve assemblyof claim 7 wherein the valve actuator further comprises: a housing; asleeve moveably disposed within the housing; and a shifting portionaffixed to the sleeve, the shifting portion being operable to move theshut-off valve between open and closed conditions upon movement of thesleeve with respect to the housing.
 9. The shut-off valve assembly ofclaim 7 wherein the valve actuator is hydraulically actuated.
 10. Theshut-off valve assembly of claim 7 further comprising a programmablecontroller operably associated with the valve actuator to cause thevalve actuator to operate the shut-off valve between open and closedconditions in accordance with a predetermined scheme.
 11. The shut-offvalve assembly of claim 10 wherein the controller is operably associatedwith the valve actuator by control of a fluid pump supplying hydrauliccontrol fluid to the valve actuator.
 12. A method of selectivelyshutting off a wellbore so that an upper portion of a completionassembly within the wellbore may be removed, the method comprising thesteps of: operably associating a wellbore shut-off valve which isoperable between open and closed conditions with a valve actuator thatcontrols movement of the valve between open and closed conditions;operating the valve actuator to move the shut-off valve to the closedcondition; and detaching and removing the upper completion assemblyportion from a lower completion portion within the wellbore after theshut-off valve has been closed.
 13. The method of claim 12 furthercomprising the steps of: reattaching the upper completion portion to thelower completion portion; and after reattaching the upper completionportion to the lower completion portion, operating the valve actuator tomove the shut-off valve to the open condition.
 14. The method of claim12 wherein the step of operating the valve actuator to move the shut-offvalve to the closed condition is conducted by a programmable controller.15. The method of claim 13 wherein the step of operating the valveactuator to move the shut-off valve to the open condition is conductedby a programmable controller.